8 BULLETIX 244, U. S. DEPARTMENT OF AGRICULTURE. 



the upper portions of its range, where associated with short leaf, this 

 difference in outline and internal branching of the crowns becomes 

 striking and serves as a distinguishing characteristic. 



In keeping with the small, close crown are the short, slender leaves 

 of shortleaf pine. The leaf characteristics, together with the cone, 

 afford the best means of identifying the species. (Fig. 2.) Special 

 notice of this is essential, because confusion prevails generally in dis- 

 tinguishing the various pines. Shortleaf belongs distinctly to the 

 two-leaf group of pines. On the more vigorous portions of the crown, 

 however, three leaves in the bundle are not uncommon. The leaves 

 are mostly 3 to 5 inches long, in some localities appearing en masse 

 of a slightly bronzed or pale-green color, in contrast to the glaucous 

 or blue-green color in other localities or regions. Short shoots and 

 colonies of sessile leaf bundles are often scattered along the trunk 

 and over the upper sides of the larger branches. These are found on 

 the pitch pine of the North and the pond pine of the South; but since 

 they occur in none of the important southern timber pines except 

 shortleaf, they serve practically as a characteristic distinguishing 

 shortleaf from both loblolly and longleaf pines. The size of the cones 

 ("burrs") aids in recognizing shortleaf when otherwise it might be 

 confounded with loblolly pine, its most common associate in the 

 lower soils. The small cones of shortleaf (from 1§ to 2\ inches in 

 length) when open on the tree appear to be about the size of pigeon 

 eggs; those of loblolly (from 3 to 5 inches in length) about the size 

 of duck eggs. The individual scales composing the cone in shortleaf 

 are armed with slender, needle-pointed prickles, broken off more 

 easily than the stouter persistent prickles of loblolly cones. The seed 

 of shortleaf (described on p. 19) is likewise much smaller than that of 

 loblolly pine. 



A difference in the bark of shortleaf and loblolly is readily per- 

 ceptible up to the beginning of old age. The bark of loblolly is on 

 the average thicker, more deeply furrowed and ridged, and somewhat 

 darker in color than that of shortleaf. After maturity these differ- 

 ences in bark become less marked, or disappear. 



RELATION OF CLEAR LENGTH TO CROWN. 



Measurements taken in shortleaf stands of average density show 

 much regularity in the relation of the length of the living crown to 

 the total height of the tree. In stands about 10 feet in height the 

 depth of the canopy averages 5 feet, or one-half the height of the 

 stand. Above this height the canopy gradually becomes propor- 

 tionately shorter, until at 80 feet clear lengths of 45 to 55 feet are 

 reached. This is from about 60 to 70 per cent of the total height, 

 varying with different qualities of site. The crown is relatively 

 longer, in proportion to the total height of the tree, on the poorer 

 situations, and, conversely, the clear length of the stem is shorter. 



